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Open Access Publications from the University of California

Scholarly Works (31 results)

  • Article
  • Peer Reviewed
The CATESOL Journal, Volume 26, Issue 1 (2014)
    Cover page: Great Writing 4: From Great Paragraphs to Great Essays (4th ed.) - Keith S. Folse, April Muchmore-Vokoun, and Elena Vestri SolomonCreative Commons 'BY' version 4.0 license
    • Thesis
    • Peer Reviewed
    UC Berkeley Electronic Theses and Dissertations (2010)

    The specific heat of a material offers a host of information about the energetics of the system, from the phonons and electrons to phase changes in the material and two-state systems. In order to measure the specific heat of small samples such as quenched high pressure materials or thin films, one must turn to microcalorimetry. This thesis discusses the application of microcalorimetry to small magnetic samples and the underlying physics illuminated by the technique.

    The thesis first describes the measurement of the spinel and olivine phases of Fe2SiO4 and the technical development necessary to measure a metastable small (10-100μg) sample, obtaining the first direct measurement of the entropy difference between the two phases.

    Focusing next on the canonical giant magneto-resistive system of Fe/Cr multilayers, first is discussed the contributions of disorder to the electrons and phonons in the system where it is determined that disorder and strain plays a dominant role in the electronic density of states for thin films of chromium and not the antiferromagnetic state of the film. Next it is determined that while sputtered Fe/Cr multilayers do exhibit an interfacial enhancement in the density of states due to interfacial alloying, the spin-dependent scattering is more dependent upon a well-defined quantum well structure.

    Finally, described herein is the development of a new calorimeter based on the ion beam-assisted deposition (IBAD) of MgO in order to measure the specific heat of thin films. After measuring the lattice parameters of the IBAD MgO through synchrotron X-ray diffraction (XRD) and proving through XRD that thin films could successfully be grown epitaxially on the device, it was used to measure the specific heat of Fe-Rh alloys with ferromagnetic and antiferromagnetic ground states. Fe-Rh alloys have been suggested for application to thermally assisted magnetic recording, but there is much debate in the literature about the theoretical origin of the AF>FM transition. By taking the difference in specific heat of the two alloys, a predicted Schottky anomaly is observed and discussed in the context of two thermal fluctuation models. Our photoemission and specific heat data show that the origin of the transition is not adequately explained by the difference in electronic densities of states.

      Cover page: Thermodynamic measurements of applied magnetic materials
      • Article
      • Peer Reviewed
      UC Berkeley Previously Published Works (2009)
      The resistivity as a function of temperature from 0.6 to 300 K for epitaxial and polycrystalline Cr thin films is presented and fit to a model which includes electron-phonon scattering and resonant impurity scattering. Resonant impurity scattering from localized defect states in the spin-density wave gap leads to very high residual resistivity (up to 400 μΩcm) and a minimum at low temperatures (below 100 K). This is strong experimental evidence for resonant impurity scattering due to defects in pure Cr rather than dopant atoms. The magnitude of the resistivity minimum scales linearly with the residual resistivity over 2 orders of magnitude. At moderate temperatures (100-300 K) the resistivity shows a positive, linear temperature dependence due to electron-phonon scattering. Defects affect the electron-phonon scattering as well leading to a variation in the effective Debye temperature and resistivity slope between samples, a significant deviation from Matthiessen's rule. © 2009 The American Physical Society.
        Cover page: Resonant impurity scattering and electron-phonon scattering in the electrical resistivity of Cr thin films
        • Article
        • Peer Reviewed
        UC Davis Previously Published Works (2018)
        Accurate staging for non-small cell lung cancer (NSCLC) is essential to guide therapy. While computed tomography (CT) and positron emission tomography (PET) scan can indicate whether mediastinal lymphadenopathy is present, histologic confirmation is required to complete the staging evaluation. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive technique associated with similar diagnostic yield and improved postoperative pain and complication rates compared to mediastinoscopy. We share the surgical technique for EBUS-TBNA based on our experience. An 81-year-old man underwent EBUS-TBNA for concurrent tissue diagnosis and mediastinal staging of a hypermetabolic left lower lobe mass and subcarinal lymph node. Our patient had no perioperative complications and was discharged home on the same day. Histologic evaluation demonstrated squamous cell carcinoma in the left lower lobe and subcarinal lymph node. EBUS-TBNA provides histologic confirmation of suspicious mediastinal lymph nodes seen on imaging. Clinicians should consider EBUS-TBNA as a mediastinal staging modality for patients with NSCLC.
          Cover page: Endobronchial ultrasound-guided transbronchial needle aspiration for staging of non-small cell lung cancer
          • Article
          Surgery (2024)
          Language barriers make it difficult for surgical teams to engage in the discussion of important aspects of pre- and post-operative patient care with patients who are non-Englishspeakers.
            Cover page: Comprehensive Interpretation Service Use for Patients who are Non-English PrimaryLanguage Speakers undergoing Surgery for NSCLC
            • Article
            • Peer Reviewed
            UC Davis Previously Published Works (2020)
            Prolonged air leak or alveolar-pleural fistula is common after lung resection and can usually be managed with continued pleural drainage until resolution. Further management options include blood patch administration, chemical pleurodesis, and 1-way endobronchial valve placement. Bronchopleural fistula is rare but is associated with high mortality, often caused by development of concomitant empyema. Bronchopleural fistula should be confirmed with bronchoscopy, which may allow bronchoscopic intervention; however, transthoracic stump revision or window thoracostomy may be required.
              Cover page: Management of Complications After Lung Resection Prolonged Air Leak and Bronchopleural Fistula
              • Article
              Family and Community Medicine (2021)
              African Americans and Latinos face significant health disparities and institutional racism. Heart and lung disease are leading factors affecting morbidity and mortality in these groups. Notably, lung cancer is the number one killer of African Americans and number two killer of Latinos1,2. African Americans are also less likely to receive surgery for lung cancer than other groups3. As such, cardiothoracic surgeons are uniquely positioned to positively affect these health outcomes, mitigate racial health disparities, and contribute to the efforts towards health equity.
                Cover page: Research Addressing Racial Health Disparities in Cardiothoracic Surgery Represents Only a Small Fraction of Total Major Meeting Peer-reviewed Content
                • Article
                • Peer Reviewed
                UC Davis Previously Published Works (2023)

                Objectives

                Determine patient and provider perspectives on widespread rapid telemedicine implementation, understand the key components of a surgical telemedicine visit and identify factors that affect future telemedicine use.

                Summary of background data

                Compared to other specialties, the field of surgery heretofore has had limited adoption of telemedicine. During the COVID-19 pandemic Healthcare, including the surgical specialties, saw new widespread use of telemedicine.

                Methods

                We conducted a prospective cohort study during the COVID-19 California stay-at-home and physical distancing executive orders. Utilization data were collected from clinics and compared to usage data during the same time 1 year later. All patients and providers who participated in a telemedicine visit during the study period were asked to complete a survey after each encounter and the surveys were analyzed for trends in opinions on future use by stakeholders.

                Results

                Over the 10-week period, the median percentage of telemedicine visits per clinic was 33% (17%-51%) which peaked 3 weeks into implementation. One hundred and ninety-one patients (48% women) with a median age of 64 years (IQR 53-73) completed the patient survey. Patients were first-time participants in telemedicine in 41% (n = 79) of visits. Fifty-seven percent (n = 45) of first-time users preferred that future visits be in-person versus 31% of prior users (p = 0.007). The median travel time from home to the clinic was 40 min (IQR = 20-90). Patients with longer travel times were not more likely to use telemedicine in the future (61% with longer travel vs. 53% shorter, p = 0.11). From the 148 provider responses, 90% of the visits providers were able to create a definitive plan with the telemedicine visit. A physical exam was determined not to be needed in 45% of the visits. An attempt at any physical exam was not performed in 84% of routine follow-up or new-patient visits, compared to 53% of post-op visits (p = 0.001).

                Conclusion

                Telemedicine is a viable ambulatory visit option for surgical specialists and their patients. During rapid telemedicine deployment, travel distance did not correlate with increased use of telemedicine, and in-person visits are still preferred. However, nearly half of all visits did not need a physical exam, which favors telemedicine use.
                  Cover page: Patient and provider perspectives to utilization of telemedicine in surgery
                  • Article
                  • Peer Reviewed
                  UC Davis Previously Published Works (2020)
                  Tobacco treatment is increasingly recognized as important to cancer care, but few cancer centers have implemented sustainable tobacco treatment programs. The University of California Davis Comprehensive Cancer Center (UCD CCC) was funded to integrate tobacco treatment into cancer care. Lessons learned from the UCD CCC are illustrated across a systems framework with the Cancer Care Continuum and by applying constructs from the Consolidated Framework for Implementation Research. Findings demonstrate different motivational drivers for the cancer center and the broader health system. Implementation readiness across the domains of the Cancer Care Continuum with clinical entities was more mature in the Prevention domain, but Screening, Diagnosis, Treatment, and Survivorship domains demonstrated less implementation readiness despite leadership engagement. Over a two-year implementation process, the UCD CCC focused on enhancing information and knowledge sharing within the treatment domain with the support of the cancer committee infrastructure, while identifying available resources and adapting workflows for various cancer care service lines. The UCD CCC findings, while it may not be generalizable to all cancer centers, demonstrate the application of conceptual frameworks to accelerate implementation for a sustainable tobacco treatment program. Key common elements that may be shared across oncology settings include a state quitline for an adaptable intervention, cancer committees for outer/inner setting infrastructure, tobacco quality metrics for data reporting, and non-physician staff for integrated services.
                    Cover page: The Emergence of a Sustainable Tobacco Treatment Program across the Cancer Care Continuum: A Systems Approach for Implementation at the University of California Davis Comprehensive Cancer Center
                    • Article
                    • Peer Reviewed
                    UC Davis Previously Published Works (2017)

                    Introduction

                    In most patients with NSCLC, the disease is diagnosed in an advanced stage, the prognosis is poor, and survival is typically measured in months. Standard therapeutic treatment regimens for patients with stage IV NSCLC typically include chemotherapy and palliative radiation. Despite newer regimens that may include molecularly targeted therapy and immunotherapy, the overall 5-year survival for stage IV disease remains low at 4% to 6%. Although therapeutic surgery is performed in a minority of cases, accumulating data suggest that thoracic surgery may play several beneficial roles for these patients.

                    Methods

                    In this narrative review, we summarize the literature on surgical intervention in the multimodality management of stage IV NSCLC, focusing on the potential evidence for and against therapeutic or curative intent procedures to affect outcomes for patients with oligometastatic disease and pleural metastasis.

                    Results

                    In selected patients, surgical resection can result in a 5-year survival rate of 30% to 50%, but this is heavily influenced by the presence of mediastinal nodal disease, which should be evaluated before therapeutic surgical procedures are undertaken. Additionally, diagnostic or palliative surgical procedures can play an important role in the personalized management of stage IV disease. These data suggest that for carefully selected patients with advanced stage NSCLC, surgical intervention can be an important component of combined modality treatment.

                    Conclusions

                    Given the advances in molecular targeted therapy and immunotherapy, further studies should focus on the possible use of surgery as a strategy of therapeutic "consolidation" for appropriately selected patients with stage IV NSCLC who are receiving combined modality care.
                      Cover page: The Role of Thoracic Surgery in the Therapeutic Management of Metastatic Non–Small Cell Lung Cancer
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